So, here begins the thread for the actual construction of an N Scale switcher for my SP&Sthemed layout.

Right from the outset, I want to make it clear that a major building requirement, (a "promise to myself")is that I want to make as much of this by myself, from scratch. So use of commercial parts, castings,3rd party casting or etching services, will be kept to an absolute minimum, if not zero.

I plan on using a commercial motor, gears, and electrical components, and screws, but hopefully not much elsefrom outside sources.

Just to keep things tied together, here's the thread on making the drivers:

The prototype looks like this (the SP&S switcher I am making is identical to an NP L-9, albeit with a different style of tender):

I have abandoned the idea of using ball bearings on the driver axles, since I tried several types and they all show poor conductivity between the axle and the outer bearing race. Even if they were to provide less friction, I am not willing to trade that for 20-30 ohm resistance paths through the drivers. So I ended up with some Bergeon bronze clock bearings that have a 1.5mm bore, are 3.5mm OD, and are 1.5mm (.0595") wide. I will mill off some flats on 2 sides so that they sit nicely in the frame slots. They fit beautifully over the 1.5mm steel axle stock I have.

Someone mentioned driver drawings and standards from the 2mm Society. I did look at their drawings.But ultimately, I made my own and I'll see where this takes me.

Here are some drawings I've made up to get started on making the frame out of brass.

Luckily, this SP&S switcher is a direct copy of an NP L-9, which I was able to get drawings for:

Say folks, take a look at those two photos. Doesn't the cab on the SP&S engine look different?I know that some SP&S engines that came from NP designs ended up getting "GN style" cabs.Sometimes even within the same class of engine, some would get the GN cabs and some wouldn't

Does that cab look different to you? It's hard to tell with the windows blocked off in different ways.I can't tell if it's just an optical illusion.

Does that cab look different to you? It's hard to tell with the windows blocked off in different ways.I can't tell if it's just an optical illusion.

Most notable to me, besies the obvious window treatment difference, is the arch of the cab roof and the trim around the number on the SP&S engine. Possibly the number of hatches on the roof too. The raised running board over the drivers on the NP loco could be contributing to optical illusion though.

I dug some info out of Ed Austin's book on these 0-6-0's. SP&S #s 1-5 were NP L-9 copies and did originally have NP cabs.But indeed, the cabs were switched to GN style in the 1930s, so that's what we're seeing in my photos above (a changed cab).

Another very odd spotting feature only on engines #4 and #5... note the single pilot ladder being ONLY on the left hand side.That isn't an accident. The engine spent its whole life that way, and was scrapped in 1951.

Good observation, Chris (about that backwards-installed power reverse).Some of the SP&S engines got a power reverse later in life. #4 did not.

The other side of #4 has a long air reservoir tank running under the running board, and also a cross compound air compressor,so that walkway is higher up on the side than the right-side walkway, and is probably the reason for the ladder.

Large-scale brass models are very handy references. Sometimes they show things that no drawing or prototype photo shows clearly enough.

I'm not saying that what you are doing is wrong (using another model for reference), but makes me wonder just how the brass manufacturers somehow came up with those hard to decipher details if they were using factory drawings and prototype photos. Did they have access to the 1:1 locomotive?